Pre-engraved projectiles and gun for firing same



June 16, 1959 s mpsou v 2,890,625

FREE-ENGRAVED PROJECTILES AND GUN FOR FIRING SAME Original Filed June14. 1951 4 Sheets-Sheet l IN V EN TOR.

Original Filed June 14, 1951 June 16, 1959 F. R. SIMPSON 2,890,525

PRE-ENGRAVED PROJECTILES AND GUN FOR FiRING SAME 4 Sheets-Sheet 2 FrankR Sim s on BY $465M MM m 4 June 16, 1959 F. R. SIMPSON ,5

PRE-ENGRAVED,PROJECTILES' AND GUN FOR FIRING SAME Original Filed June14. 1951 4 Sheets-Sheet :s

' INVENTOR. Frank Elfin-[ aun BY F. R. SIMPSON June 16, 1959FREE-ENGRAVED PROJECTILES AND GUN FOR FIRING SAME 4 Sheets-Sheet 4Original Filed June 14. 1951 INVENTOR. Frank. R. iirn scm JmAQQQ sia.

I a 551 v nited States FEE-ENGRAVED PROJECTILES AND GUN FOR FIRING SAJMEFrank R. Simpson, Upper Darby, Pa., assignor to the United States ofAmerica as represented by the Secretary of the Army 1 Claim. (Cl. 8934)This invention relates to pre-engraved ammunition for use with rifledguns; In the usual fixed round of ammunition, the projectile has arelatively narrow soft metal driving band extending thereabout andrigidly fixed therewith. This band has an outer diameter substantiallyequal to twice the radial distance from the bore axis of the barrel tothe bottom of the grooves of the rifling so that as to the projectile isdriven along the barrel, its driving band is scored or engraved by theriflng of the barrel and the projectile is constrained to follow thehelical rifling and thereby to acquire the necessary stabilizing spin.

This application is a division of my application Serial No. 231,493,filed June 14, 1951, now Patent No. 2,804,- 896, dated Sept. 3, 1957.

The present invention contemplates the use of fixed ammunition orcartridges the projectiles or bullets whereof are pre-engraved, that is,provided with helical splines which initially fit smoothly between thelands of the barrel riflng and create a minimum of friction with thebarrel surface, while effecting a substantially gastight relationtherewith. In an obvious manner, such projectiles reduce wear andfriction, increase muzzle velocity for the same propelling charge andincrease the useful life of the barrel.

While having great advantages, the use of pre-engraved projectiles inrapid-fire guns, requires that each cartridge be in such a rotationalposition at the instant it is rammed into the breech, that the splineson its bullet will register or mesh accurately with the grooves of therifling. Otherwise jamming and interference may occur between theengraved projectile and lands of the rifling and impair the operation ofthe gun.

The foregoing considerations make it desirable that each cartridge befed to the breech of the gun, with its projectile positively positionedand held in the aforesaid rotational position; and in order to eflfec-tthis function, I propose to form the base of each cartridge case withindexing means such as a centrally offset notch, groove or lug whichwill cooperate with the belt or clip as well as with the loadingmechanism of the gun, to feed each cartridge into the gun and load itinto the breech, in proper rotational position. Then when each cartridgeis assembled with its pre-engraved bullet so that its splines bear acertain or predetermined angular relation with the aforesaid indexingmeans of the cartridge case, proper loading of each cartridge is assuredand the benefits and advantages of pre-engraved ammunition are fullyexploited.

It is the object of the present invention to provide a clip particularlyadapted to held several rounds of ammunition in side-by-side contactingrelation so that each round is held in the desired fixed rotationalposition until the clip is inserted into the loading mechanism of thegun and engaged thereby in cooperation with the indexing means of theround until the latter is rammed atent 2,890,625 Patented June 16, 1959into the gun in the desired meshing relation with the rifling.

A further object is, to provide a cartridge of the type aforesaidconstructed to cooperate with the clip and loading mechanism of the gunto afford the necessary fixed rotational position during feeding to thegun and loading.

Another object is to provide the combination of a clip and plurality ofrounds of ammunition which will enable the benefits of pre-engravedammuntion to be realizedto the fullest extent. r V

A still further object is to provide the loading mechanism and tray of a40 mm. automatic gun, with means cooperating with the cartridgegenerallyand particularly with the aforesaid indexing means of its case,to positively control the rotational position of the cartridge from thetime it leaves its clip until it is rammed into the breech with thesplines upon its bullet in proper meshing relation with the rifling ofthe barrel.

Another object is to provide a system or mechanism wherein therotational position of the cartridge and its indexing means ispositively controlled from the time it is loaded into its clip untilrammed into the breech of the gun.

Other objects and advantages will be apparent after a study of thefollowing detailed description in connection with the accompanyingdrawings.

In the drawings:

Figure 1 is a side elevation of a clip holding four cartridges. V

Figure 2 is an end elevation of the clip of Figure 1 with one cartridgeremoved.

Figure 3 is a cross-section to an enlarged scale, taken upon the line33, Figure 2.

Figure 4 is a cross-sectional view of a clip and cartridge in the loaderof a 40 mm. automatic gun, taken upon line 44, Figure 11, and showingthe way in which the cartridges are released from the clip as they arefed downwardly with respect to the loader.

Figure 5 is an end view of a cartridge provided with one type ofindexing means.

Figure 6 is an end view of a cartridge provided with a second type ofindexing means.

Figure 7 is a sectional view, taken in a vertical axial plane of a 40mm. automatic gun and showing portions of the loader and cartridge tray,with means to positively guide the lowermost cartridge into the tray infixed predetermined rotational position.

Figure 8 is a perspective view of the loading tray showing alongitudinal guide rail thereon for guiding the cartridges in axialtranslation only, during ramming.

Figure 9 is an end view of the loading tray and a portion of the loader,showing the guide rail in end elevation and a latch in the loader whichmay be used, if desired, to hold each cartridge with its indexing notchfit-. ting over and about the guide rail during the initial stage oframming.

Figure 10 is a perspective view of the rear portions of the automaticloader with a clip of ammunition therein, together with a portion of theloading tray.

Figure 11 is a sectional View taken in a vertical plane indicated by theline 1111, Figure 10.

Figure 12 is a perspective view showing the feed rollers and indexingmeans of a standard 40 mm. automatic gun.

Figure 13 is a vertical section through a portion of the gun showing aspecial attachment for guiding a round of ammunition in fixed rotationalposition from the time it leaves the clip until it is deposited by thefeed rollers upon the loading tray. In this figure a round has justbegun its downward movement from clip to tray.

Figure 14 is a view corresponding to Figure 13 but showing how theattachment is released from the round in response to depositing of theround upon the tray.

Figure 15 is a view corresponding to Figures 13 and 14 but showing theposition of the attachment formmg a part of the invention when an emptycartridge case is ejected in the direction of the arrow. I

Figure 16 is an exploded view of the detent and spring forming portionsof the aforesaid attachment, and

Figures 17 and 18 are views showing the latch structure in detail.

Referring in detail to the drawings, 1 identifies in general a clipadapted to hold four rounds of cartridges and comprising a channelelement 2 generally U-shaped in cross-section and having four arcuatenotches in its upstanding sides, as indicated at 3, Figure 2. As shownat 4, upon Figure 3, one side wall of the channel element is offsetinwardly toward the other side wall, whereby to form a rim or ledge of aminimum depth substantially equal to the width of radial dimension ofthe flange of the cartridge head. As seen in Figure 1, the clip isslightly curved longitudinally on radii corresponding to those of theautomatic loader guides, whereby adjacent rounds remain in contact attheir rims as well as at a point near the forward ends of the cartridgecases. See Figure 7.

At each of four points along its length, corresponding to its four mostnarrow dimensions, the clip is provided with a non-circular rod 5slidably mounted for longitudinal movement and urged to the right, asviewed in Figure 3, by a spring 6 acting between the wall of the clipand a flange 5w fixed to the rod. In the position shown, the inner endof the rod projects from the clip so that, when forced inwardly againstthe action of spring 6, a clamp member 7 rigidly attached to the otherend of the rod, is moved rearwardly away from the clip to release therim of the cartridge case C.

The foregoing described construction is standard equipment for theautomatic loader of the Armys 40 mm. gun and per se, forms no part ofthe present invention. When this clip is used with standard ammunition,there is no necessity to locate the rounds within the clip in anyparticular rotational position. Each round is loaded simply by manualpressure on the end of pin 5, insertion of the round into its notches,and release of the pin. The rounds are thus held in the position shownupon Figures 1 to 3, and, together with the clip, are slipped downwardlybetween the front and rear guides of the automatic loader for firing.

Where pre-engraved ammunition is to be used, I propose to load eachround into its clip in the same fixed predetermined rotational positionand to include in the automatic loader of the gun itself, means by whichthe aforesaid rotational position of each round is maintained until itis rammed into the breech. For this purpose, I provide a chordal channelor groove 8 in the head of each cartridge. In addition, the circulargroove in the head of each cartridge is provided with a pair of pins 9and 10 spaced linearly a distance equal to the width of the clampmembers 7 and in a direction parallel to grooves or channels 8, as willbe clear from inspection of Figures 2' and 5. The pins have a projectinglength substantially equal to the depth of the circular groove 11 inwhich they are positioned so that their ends are flush with the heads ofthe cartridge cases.

Figures 2, 3, 4, and 11 show that the end of each clamp member 7 isturned inwardly to form a lug fitting between the two pins and that whenthe rounds are so positioned in the clip, the grooves 8 are in alignmentin the longitudinal direction of the clip, that is, the direction ofmovement of the clip and cartridges within the automatic loader of thegun. This automatic loader includes a forward guide 12, Figure 7, havinga channel to receive and guide the noses of the splined bullets B,a-rear guide 13 to receive and guide the heads of the cartridge cases,and automatic feed mechanism generally indicated at 14, but not shown indetail. In a manner subsequently described, this feed mechanism isoperated by movement of the loading tray in recoil and counterrecoil.The forward guide 12 is generally an arcuate upstanding channeled memberflaring at its top and adapted to guide the noses of the bullets indownward movement into the gun. The rear guide as shown in Figures 4, 7and 10, comprises a channeled member having a backing plate 15 and sides16 and 17 rigidly secured thereto to provide a longitudinally arcuate,generally vertical channel slidably receiving the heads of thecartridges and the clip and guiding them properly when moved downwardlyby the feed mechanism 14 of the gun in timed relation with the loadingtray, to feed a cartridge thereonto at the proper instant during recoil.

The backing plate 15 is formed with a forwardly and vertically extendingridge 15a which engages the heads of the cartridges within the feedingmechanism and spaces them forwardly a distance suflicient to provide aspace enabling clamp members 7 to be moved rearwardly to release thecartridges from the clip as they are moved downwardly in the loader.This release is eifected by a cam plate 18 secured to or integral with,side 17, as shown in Figure 4, and having a cam surface 18a, Figure 11,which engages the projecting ends of the clip pins 5 as the clip and itscartridges slide downwardly in the loader, and forces the clamp members7 rearwardly to thereby release the lower cartridge from the clip. Inthis way, as feed mechanism 14 is operated in response to counterrecoilmovement of the barrel and loading tray, to move the cartridges one stepdownwardly, the lowermost cartridge is forced between the feed rollers21 and 22, shown at Figure 12, and subsequently described. The feedmechanism of the gun, as just described is of standard construction. Inaddition, I provide a strip or rail 19 fixed to plate 15, spaced fromand parallel to ridge 15a and so positioned and of a length suflicientto engage within the aligned grooves 8 in the cartridge heads duringtheir downward travel in the loader and until the cartridges, insequence are gripped by the heads of the rammer levers. By thisprovision the cartridges are maintained in fixed rotational positionsfrom the time they are loaded into the gun with their clip until theyare deposited in sequence upon the loading tray 20.

In the gun described, the loading tray is rigidly secured to the breechring and projects rearwardly therefrom and recoils as a unit therewith.This tray has cam grooves 42 and 43 along its right and left sides, andas the barrel, breech ring and tray move forwardly in counterrecoil,feed rods having rollers at their lower ends riding in the respectivecam grooves, are moved downwardly by the grooves to move all cartridgesin the loader and their clip, down one step after the empty case of thecartridge previously fired has been ejected. A pair of laterally-shaped,longitudinally-extending feed rollers 21 and 22 are carried by theloading mechanism for positive support of the lowermost cartridge in theloader. These rollers which are in the shape of four-pointed stars incross section (see Figure 12) are mounted in side-byside fore and aftrelation immediately below the lowermost cartridge in the loader. Eachrod is mounted at its forward ends for pivotal movement about arespective axis as indicated at 25 and 26, which axes are parallel,vertical and normal to the axis of rotation of the rollers, whereby theseparation of the rollers may vary. This separation is yieldinglyresisted by spring-pressed indexing plungers 27 and 28 engagingrespective star index wheels 29 and 30 each rigidly attached to arespective feed roller. The relation of. the plungers, index Wheels andfeed rollers is such that the latter are yieldingly held in positionconjointly forming an upwardly-facing semicircular channel into whichthe lowermost cartridge is forced by the feed mechanism. This movementforces the feed rollers and index wheels to rotate one-quarter rotationand insures that but one cartridge may be deposited upon the feed trayfor each reciprocation thereof in recoil and counterrecoil. The pivotalmounting of the feed roller shafts enables the rollers to separateslightly and continuously grip a cartridge as it passes therebetween.The rollers are normally locked in position by catch heads 31 and 32mounted upon respective spindles 33 and 34. During counterrecoil, whenthe cartridges are being depressed by the feed mechanism to deposit thelowermost cartridge upon the tray, the loading tray pawls 35 and 36,Figure 8, engage and rotate the catch heads. This action releases thefeed rollers and permits them to be revolved by the cartridge in themanner previously described. When the cartridge has passed between thefeed rollers and the rollers have rotated onequarter turn, the catchheads are returned to their normal positions by torsion springs such as37, shown in Figure 12 for catch 31. This again locks the rollers inposition until released by the next reciprocation of the tra The upperends of the rammer leaves are indicated at 38 and 39, Figure 8. Theselevers are independently pivoted on a common rammer rod (not shown), asthe gun and tray move in counterrecoil toward battery position. Therammer levers project upwardly through respective cam slots 40 and 41 inthe loading tray. These slots have oppositely-disposed riser portions40a and 4112 each connecting straight parallel portions at differenttransverse distances from the central longitudinal axis of the tray. Aspreviously described the automatic feed mechanism is operated by rollersnot shown, riding in respective cam slots or channels 42 and 43 formedupon the tray 20. See Figures 7 and 8. These slots have riser portions42a and 43a, each connecting two parallel sections, such as 42b and 420and act to raise the feed pawls during recoil and then to lower them atthe proper time during counterrecoil to efiect the aforementioneddownward feeding of the cartridges and to move the lowermost cartridgebetween feed rollers 21 and 22, and to reposit it upon the tray.

Forward movement of the tray with the gun barrel in counterrecoil actsto tension a rammer spring, not shown, which then acts to urge therammer arms forwardly in their slots 40 and 41. The active or riserportions 40a and 41a of slots 40 and 41 are so positioned longitudinallyof the tray, with respect to the active portions 42a and 43a of channels42 and 43, that the upper ends of rammer levers 38 and 39 are movedinwardly toward each other at the instant the feed mechanism is operatedto deposit a cartridge upon the tray. At that instant, of course, therim or head of the deposited cartridge is coplanar with the rammerlevers so that as the rammer levers move toward each other they grip thehead of the cartridge between them. At this time the rammer levers arelatched in rearwardrnost position while the gun and tray are moving incounterrecoil toward battery position. The breechlock of the gun is, ofcourse, fully open.

As the barrel and tray near battery position loading tray pawls 35 and36 trip the catch holding the rammer lever and arms 38 and 39 inretracted position and the now-compressed rammer spring throws the armsand the cartridges gripped between them, forwardly at extremely highspeed. As the arms move forwardly past the riser or active portion 40aof their slots, they are separated. The cartridge is released and movesforward under its own momentum into the breech. Movement of thecartridge into the breech releases the breechlock in a Well-known mannerwhich, on closing, fires the gun when in automatic fire.

In view of the fact that there might otherwise be a short period afterthe cartridge leaves guide strip 19 until it is gripped by rammer levers38, 39 and other- '6 wise held in rotational position upon the tray, Ihave provided a detent mechanism which, in effect, forms a continuationof strip 19 and moves downwardly with the cartridge until the latter isgripped by the rammer levers.

This detent or guide mechanism comprises a plunger element 44 having ahead 44a slidably fitting a bore 45 formed in the loader frame. Theplunger is limited to reciprocation only and is urged upwardly by a coilspring 46 into the normal position shown upon Figure 15. The plungerelement has a forwardly-offset end portion 44b. This portion has itsforward vertical edge so shaped and normally positioned to form acontinuation of guide strip 19, as will be noted from Figure 15, wherebythe rotational position of the lowermost cartridge is controlled only bythe detent or guide mechanism by reason of its engagement within theindexing groove in the cartridge head.

A latch generally identified by the numeral 47 in Figures 13, 14 and 15,and shown in greater detail upon Figures 16, 17 and 18, is carried bythe lower end of offset portion 441;. The latch may conveniently havethe general form shown upon Figure 16, pivoted to the plunger on atransverse axis defined by aligned holes 48 and urged into clockwiserotation as viewed in Figures 13, 14 and 15, by a leaf spring 49 havingforwardly offset lateral projections 4%. These projections engage therespective side walls of latch 47 and urge the same into a rotationposition wherein the nose portion 47a projects forwardly into a positionto be engaged by the rim of the lowermost cartridge, as shown by Figure15. Rotation of the latch is limited to the position shown on Figures 13and 15 by engagement between the edges of projections 47b, with the endsof a pin 50 having a press fit within a transverse bore in plunger 44.The base of the latch has rearwardly-projecting arms 47c, Figure 16, toand between which there is secured an anti-friction block 51, Figures 17and 18. This block projects below the lower edges of the arms 47c and,being rearwardly offset from the axis of holes 48 pivots the latchcounterclockwise when moved into contact with the surface of loadingtray 20.

By the construction just described, as the lowermost cartridge is forceddownwardly by the feed mechanism, in the manner previously described,its engagement with nose 47a of latch 47, causes the entire plungerelement to move downwardly as a unit with the cartridge until, whenblock 51 strikes the loading tray, the latch 47 is pivoted to removenose 47a from the rim of the cartridge. Whereupon, spring 46 causes theentire plunger element to snap back into the position shown in Figure 15wherein the forward edge of portion 44b engages within the indexinggroove 8 of the next cartridge.

It will thus be seen that the construction just described maintains eachcartridge, as it is fed downwardly from the feed mechanism to theloading tray, in fixed rotational position and acts to maintain suchposition until the cartridge rests upon the tray and is engaged by therammer arms as previously described.

It is contemplated that the rammer levers alone may be sufiicient tomaintain the cartridge in proper rotational position upon the loadingtray until it is released therefrom by the action of the active or riserportions 40a and 41a of slots 40 and 41, and thrown forwardly at highvelocity into the breech. However in addition to the gripping action ofthe rammer levers, I provide a guide rail 52, rigidly secured to theloading tray longitudinally thereof and so positioned and shaped as toengage within the notch in the rim of the cartridge case, such as 8a,Figure 5. This guide rail is in the same longitudinal vertical plane asguide strip 19 so that, as the lowermost cartridge in the loader ormagazine is guided downwardly without rotation, the notch in the rim ofits head fits over and engages the rail. This acts to prevent angularmovement of the cartridge during the instant its rim is gripped by therammer levers. As the guide rail extends throughout the length of theloading tray, as shown upon Figure 8, the correct angular position ofthe cartridge is maintained after it has been released by portions 4tlaand 41a of the cam slots as the rammer rod and its arms are movedforwardly relatively to the tray. The cartridge is thus positivelyguided to prevent its rotation or angular movement about its longitudinal axis from the time it is loaded into the magazine or loader,until it is rammed into the breech with the splines of its bullet inproper registration with the rear terminals of the rifling grooves ofthe barrel.

Due to the high speed with which the cartridge is rammed into thebreech, and with which the empty case is thrown rearwardly by theextractors, it is desirable to provide some means for exerting adownward force upon the cartridge during its forward movement with andalso relatively to, the tray, as well as during the rearward movement ofthe empty cartridge case. For this purpose, I have provided a yieldingor flexible detent 53, Figures 7 and 9. This detent is pivoted at oneend, as indicated at 54, Figure 9, on a longitudinal axis and is urgedinto clockwise rotation, as viewed, by a spring 55. The detent ispositioned on the automatic loader just beneath and forwardly of thefront cartridge guide 12 so that the nose of each cartridge just clearsthe same as it is fed downwardly onto the tray. The detent is limited indownward pivotal movement, by any suitable stop mechanism, not shown, tosubstantially the position shown upon Figure 9. Hence, as the cartridgeis moved forwardly, the nose of its bullet passes beneath the detent andpivots the same upwardly against the force of spring 55. The detent thusexerts a downward force upon the cartridge which prevents it frombouncing upon the tray. As the empty cartridge case is thrown rearwardlyby the extractors, its rim again cams detent 53 slightly upwardlywhereby the empty case is held with the notch in its head fitting overrail 52 so that the correct rotational position of the empty case ismaintained until it is clear of the gun.

When cartridges having index means of the type shown upon Figure 6 areused, it is contemplated that the loading tray will be provided with twospaced parallel guide rails similar to rail 52, each positioned to fit arespective notch 8b and 8c in the cartridge rim, thus aifording addedprotection against axial rotation of the cartridge and empty case.

I have thus provided a complete system particularly adapted for theautomatic gun described wherein preengraved ammunition may be usedwithout danger of jamming and the great benefits and advantages thereofutilized and exploited to the fullest extent. Any minor rotationalmisalignment between the cartridge and the riding at the breech will becorrected by the tapered or pointed ends of the splines upon the bullet,as indicated upon Figure 7 and as described in my United States LettersPatent No. 2,659,262 issued November 17, 1953, wherein is disclosed andclaimed an apparatus for assemblying pre-engraved bullets in properpredetermined angular relation with respect to the indexing slot and fornotches upon the head of the cartridge case.

In the claims, the term indexing means comprehends the slot 8 or 8 asshown in Figures 5 and 6 respectively, and at least one notch in thecartridge rim, such as 8a, Figure 5, or 81) or 30, Figure 6. The termmeshing relation means an angular or rotational position of thecartridge with respect to the breech wherein the splines upon thepreengraved projectile of the cartridge will freely enter between thelands of the rifling of the barrel at the breech end thereof, by astraight axial translation of the cartridge and without any substantialrotation thereof. By ramming position is meant a position of thecartridge rearwardly of the breech and in axial alignment with the boreof the gun whereby loading into the breech may be effected by a pureaxial translation of the cartridge. The term transverse as applied tothe groove or channel in the head of the cartridge case, means at rightangles to the central longitudinal axis of the cartridge.

Having now fully disclosed the invention, what I claim and desire tosecure by Letters Patent is:

In combination, a plurality of cartridges each comprising a cylindricalcase having a circular channel and an offset transverse groove in itshead thereof, a pair of spaced pins fixed in and extending outwardlyfrom the base of said circular channel to a length equal to the depth ofsaid circular channel, a pre-engraved projectile secured in and closingthe forward end of each said cylindrical case, a clip for receiving theheads of said plurality of cartridges and to maintain same in side byside relation comprising, a unitary, longitudinally curved U-shapedchannel member having upstanding forward and rearward walls, there beinga plurality of accurate notches in said upstanding walls thereof, therearward wall of said channel being offset inwardly toward the forwardwall to define a ledge having a minimum depth substantially equal to theradial dimension of the flange of a said cartridge case head, aplurality of transversely disposed non-circular rods slidably mounted insaid channel member and below said ledge, each said rod beingdiametrically spaced with respect to a corresponding accurate notch, aflange fixed on each said rod between the Walls of said channel element,a coil spring encircling each rod between said flange and an adjacentside wall normally urging said rod in a forward direction, and anupstanding clamp member rigidly fixed on the rearward end of each saidrod, each said clamp member being turned inwardly at its uppermost endto enter a said circular channel in a respective cartridge case head andbetween a said pair of pins in said circular channel whereby saidcartridge case and its projectile are held against rotational movement.

References Cited in the file of this patent UNITED STATES PATENTS

